JP2002081881A - Condensation accelerating heat exchanger tube and method for condensing non-eutectic mixed refrigerant - Google Patents
Condensation accelerating heat exchanger tube and method for condensing non-eutectic mixed refrigerantInfo
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- JP2002081881A JP2002081881A JP2000265021A JP2000265021A JP2002081881A JP 2002081881 A JP2002081881 A JP 2002081881A JP 2000265021 A JP2000265021 A JP 2000265021A JP 2000265021 A JP2000265021 A JP 2000265021A JP 2002081881 A JP2002081881 A JP 2002081881A
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- Prior art keywords
- grooves
- groove
- heat transfer
- tube
- condensation
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- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Landscapes
- Compression-Type Refrigeration Machines With Reversible Cycles (AREA)
- Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)
Abstract
Description
【0001】[0001]
【技術分野】本発明は、凝縮促進型伝熱管及び非共沸混
合冷媒の凝縮方法に係り、特に、管内を150kg/
(m2 ・s)以下の低冷媒質量速度で流通せしめられる
非共沸混合冷媒を凝縮せしめる凝縮器に好適に用いられ
る凝縮促進型伝熱管と、かかる低冷媒質量速度で、伝熱
管内を流通せしめられる非共沸混合冷媒を有利に凝縮せ
しめ得る凝縮方法に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a condensation promotion type heat transfer tube and a method for condensing a non-azeotropic refrigerant mixture, and more particularly to a method for condensing 150 kg / tube inside the tube.
A condensation promoting heat transfer tube suitably used for a condenser for condensing a non-azeotropic mixed refrigerant flowing at a low refrigerant mass speed of (m 2 · s) or less, and flowing through the heat transfer tube at such a low refrigerant mass speed The present invention relates to a method for condensing a non-azeotropic mixed refrigerant to be advantageously condensed.
【0002】[0002]
【背景技術】従来から、ルームエアコンやパッケージエ
アコン等の如き空調用熱交換器に組み込まれる凝縮促進
型伝熱管の一種として、管内面に多数の溝が設けられて
なる、所謂、内面溝付伝熱管が、用いられてきている。
そして、一般に、この内面溝付伝熱管は、管内面に形成
される溝の形態によって、幾つかの種類に分かれてお
り、例えば、特開平7−12483号公報等に示される
如き、多数の螺旋溝が管軸方向に連続して延びるように
形成されてなる螺旋溝付伝熱管や、特開平9−2627
9号公報等に開示されるような、V字状を呈する多数の
溝が管軸方向に配列されてなる松葉溝付伝熱管、或い
は、特開平3−234302号公報等に明らかにされる
如き、螺旋溝からなる多数の主溝と、該多数の主溝に対
して交差して延びる多数の副溝とが形成されてなるクロ
ス溝付伝熱管等が、代表的なものとして、知られてい
る。2. Description of the Related Art Conventionally, as a type of condensation promoting heat transfer tube incorporated in an air conditioner heat exchanger such as a room air conditioner or a package air conditioner, a so-called inner grooved transfer tube having a plurality of grooves provided on the inner surface of the tube. Heat tubes have been used.
Generally, this heat transfer tube with an inner surface groove is divided into several types depending on the form of a groove formed on the inner surface of the tube. For example, as shown in Japanese Patent Application Laid-Open No. 7-12483, a number of spirals are used. A heat transfer tube with a spiral groove formed so that the groove extends continuously in the tube axis direction;
No. 9, JP-A-9-234302, etc., as disclosed in JP-A-3-234302, etc., such as disclosed in Japanese Patent Application Laid-Open No. 3-234302, in which a number of V-shaped grooves are arranged in the tube axis direction. A cross grooved heat transfer tube in which a number of main grooves formed of spiral grooves and a number of sub-grooves extending to intersect with the number of main grooves are formed is known as a typical example. I have.
【0003】ところで、上述の如き空調用熱交換器にお
いては、その冷媒として、従来、HCFC−22やHC
FC−12等の単一冷媒が一般に用いられていたが、近
年では、環境保全等の観点から、それらの単一冷媒に代
えて、HFC−32とHFC−125とHFC−134
aをそれぞれ所定の割合にて混合してなる冷媒や、HF
C−32とHFC−125を混合した冷媒等、所謂、非
共沸混合冷媒が多く用いられるようになってきている。
このため、最近の空調用熱交換器における凝縮促進型伝
熱管には、冷媒として、非共沸混合冷媒を用いた場合に
あっても、優れた凝縮性能が発揮され得るようになって
いることが求められているのである。Incidentally, in the above-described air-conditioning heat exchanger, HCFC-22 or HCFC-22 is conventionally used as the refrigerant.
Although a single refrigerant such as FC-12 has been generally used, in recent years, from the viewpoint of environmental protection and the like, HFC-32, HFC-125 and HFC-134 have been used instead of the single refrigerant.
a mixed with each other at a predetermined ratio, HF
A so-called non-azeotropic refrigerant mixture such as a refrigerant mixture of C-32 and HFC-125 has been increasingly used.
For this reason, the condensation promotion type heat transfer tubes in recent heat exchangers for air conditioning can exhibit excellent condensation performance even when a non-azeotropic mixed refrigerant is used as the refrigerant. Is required.
【0004】かかる状況下、特開平8−75384号公
報には、非共沸混合冷媒を用いた空調用熱交換器の凝縮
促進型伝熱管として、前述せる如き内面溝付伝熱管のう
ち、クロス溝付伝熱管が、有利に用いられ、非共沸混合
冷媒に対して、高い凝縮熱伝達率が得られることが、明
らかにされている。Under these circumstances, Japanese Patent Application Laid-Open No. 8-75384 discloses a cross-condensation-type heat transfer tube as described above as a condensation promoting heat transfer tube for an air conditioning heat exchanger using a non-azeotropic mixed refrigerant. It has been found that a grooved heat transfer tube is advantageously used and provides a high condensation heat transfer coefficient for non-azeotropic refrigerant mixtures.
【0005】ところが、本発明者等が、そのような開示
事項を検証すべく、前記公報に開示された構造を有する
クロス溝付伝熱管を用いて、公知の凝縮性能試験を行っ
たところ、冷媒質量速度が150kg/(m2 ・s)以
下の低冷媒質量速度域となると、管内を流通せしめられ
る非共沸混合冷媒に対する撹拌作用が十分に得られなく
なって、管内面に、非共沸混合冷媒特有の濃度境界層が
形成され、それによって、管内凝縮熱伝達率が著しく低
下してしまうことが明らかとなったのである。そして、
このことから、従来のクロス溝付伝熱管が組み込まれた
空調器用熱交換器では、最も運転時間の長い中間能力運
転域において、凝縮能力の極端な低下が惹起されること
も、判明したのである。However, in order to verify such disclosures, the present inventors conducted a well-known condensation performance test using a cross-grooved heat transfer tube having the structure disclosed in the above publication. When the mass velocity is in the low refrigerant mass velocity range of 150 kg / (m 2 · s) or less, the stirring effect on the non-azeotropic mixed refrigerant flowing through the pipe cannot be sufficiently obtained, and the non-azeotropic mixing It has been found that a concentration boundary layer unique to the refrigerant is formed, which significantly reduces the condensation heat transfer coefficient in the pipe. And
From this, it was also found that in the air conditioner heat exchanger incorporating the conventional cross-grooved heat transfer tubes, an extreme decrease in the condensation capacity was caused in the intermediate capacity operation range where the operation time was longest. .
【0006】[0006]
【解決課題】ここにおいて、本発明は、上述せる如き事
情を背景にして為されたものであって、その解決課題と
するところは、非共沸混合冷媒が、管内を、150kg
/(m2 ・s)以下の低冷媒質量速度で流通せしめられ
る際における管内凝縮熱伝達率の低下が可及的に抑制さ
れ得、以て、空調機用熱交換器の中間能力運転域におけ
る凝縮能力を有利に高め得る凝縮促進型伝熱管を提供す
ることにある。また、本発明にあっては、伝熱管内を、
150kg/(m2 ・s)以下の低冷媒質量速度で流通
せしめられる非共沸混合冷媒を効率的に凝縮せしめるこ
とが出来る、非共沸混合冷媒の凝縮方法を提供すること
を、その第二の解決課題とするものである。The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a non-azeotropic mixed refrigerant in which 150 kg of gas flows through a pipe.
/ (M 2 · s) or less at a low mass flow rate of the refrigerant, the decrease in the condensed heat transfer coefficient in the pipe can be suppressed as much as possible. It is an object of the present invention to provide a condensation promotion type heat transfer tube which can advantageously increase the condensation capacity. Further, in the present invention, the inside of the heat transfer tube,
The second object of the present invention is to provide a method for condensing a non-azeotropic mixed refrigerant capable of efficiently condensing a non-azeotropic mixed refrigerant flowing at a low refrigerant mass velocity of 150 kg / (m 2 · s) or less. Is a problem to be solved.
【0007】[0007]
【解決手段】そして、本発明にあっては、かかる課題の
解決のために、管内を150kg/(m2 ・s)以下の
低冷媒質量速度で流通せしめられる非共沸混合冷媒を凝
縮せしめるための凝縮促進型伝熱管において、管内面
に、管軸に対して20〜40°の捻れ角と0.20〜
0.35mmの深さとを有する第一の溝が、管軸方向に
連続して延びるように複数形成されると共に、該第一の
溝の捻れ角に対して±5°の範囲内の大きさの捻れ角
と、該第一の溝の深さに対して±0.05mmの範囲内
の深さとを有する第二の溝が、管軸に平行な直線を該第
一の溝との間に挟むようにして、該第一の溝と交差しつ
つ、管軸方向に連続して延びるように複数形成されて、
それら複数の第一の溝と第二の溝のうち、周方向に隣り
合う二つの第一の溝と二つの第二の溝とにて囲まれてな
る突起が、0.15〜0.40mmの高さと、該第一及
び第二の溝のそれぞれの幅よりも小さい長さの四つの底
辺を有する四角錐台形状をもって、該第一の溝と該第二
の溝を介して千鳥状に、相互に独立して、多数形成され
ていることを特徴とする凝縮促進型伝熱管を、その要旨
とするものである。According to the present invention, a non-azeotropic mixed refrigerant that is circulated in a pipe at a low mass flow rate of 150 kg / (m 2 · s) or less is condensed. Of the condensation promoted heat transfer tube of (1), a torsion angle of 20 to 40 ° with respect to the tube axis and 0.20 to
A plurality of first grooves having a depth of 0.35 mm are formed so as to extend continuously in the tube axis direction, and have a size within a range of ± 5 ° with respect to the twist angle of the first grooves. And a second groove having a torsion angle of ± 0.05 mm with respect to the depth of the first groove, a straight line parallel to the tube axis is formed between the first groove and the second groove. As it is sandwiched, a plurality is formed so as to extend continuously in the tube axis direction while intersecting with the first groove,
Among the plurality of first grooves and the second grooves, the protrusions surrounded by two first grooves and two second grooves adjacent in the circumferential direction are 0.15 to 0.40 mm. Height and a truncated quadrangular pyramid shape having four bases with a length smaller than the width of each of the first and second grooves, in a staggered manner through the first and second grooves. In addition, the present invention provides a condensation-promoting heat transfer tube characterized by being formed in large numbers independently of each other.
【0008】すなわち、この本発明に従う凝縮促進型伝
熱管にあっては、管内面に、第一の溝と第二の溝とが、
略同一の深さと、管軸に対する略同一の大きさの捻れ角
とをもって、管軸に平行な直線を間に挟むようにして、
互いに交差しつつ、管軸方向に連続して延びるように、
それぞれ複数形成されていることによって、四角錐台形
状を呈する所定高さの突起が、管内面に、千鳥状に配置
された状態で、相互に独立して、多数形成されていると
ころから、多数の突起の間を流通せしめられる非共沸混
合冷媒が、第一の溝と第二の溝に沿って、それぞれバラ
ンス良く流動せしめられつつ、それら多数の突起に衝突
して、乱流が効果的に促進され得るのであり、また、そ
のような多数の突起間を流通せしめられる非共沸混合冷
媒において、第一の溝と第二の溝に沿って流通せしめら
れる冷媒と、突起の斜面や斜辺に沿って流通せしめられ
る冷媒との間に、速度分布が生じ、それによっても、非
共沸混合冷媒の乱流促進が、より有効に図られ得るので
ある。That is, in the condensation promoting type heat transfer tube according to the present invention, the first groove and the second groove are formed on the inner surface of the tube.
With approximately the same depth and a torsion angle of approximately the same size with respect to the tube axis, sandwiching a straight line parallel to the tube axis,
While intersecting each other, extending continuously in the tube axis direction,
Since a plurality of projections each having a predetermined height in the shape of a truncated quadrangular pyramid are formed on the inner surface of the pipe in a staggered manner, a large number of projections are formed independently from each other. The non-azeotropic mixed refrigerant circulated between the protrusions of the first and second grooves is caused to flow in a well-balanced manner along the first groove and the second groove, and collides with these many protrusions, thereby effectively suppressing turbulent flow. In the non-azeotropic refrigerant mixture that is allowed to flow between such a large number of protrusions, the refrigerant that is allowed to flow along the first groove and the second groove, and the slopes and hypotenuses of the protrusions Velocity distribution is generated between the refrigerant and the refrigerant circulated along the flow path, whereby the turbulence of the non-azeotropic refrigerant mixture can be more effectively promoted.
【0009】しかも、本発明に係る凝縮促進型伝熱管に
おいては、特に、四角錐台形状を呈する突起の高さが
0.15〜0.40mmの範囲とされると共に、かかる
突起の四つの底辺が、何れも、第一溝と第二の溝の幅よ
りも小さくされているため、突起の一つ一つが、非共沸
混合冷媒の突起との衝突による乱流促進を生じさせるの
に十分な大きさを確保した上で、可及的に小さく為され
ており、それによって、各突起の間を流通せしめられる
非共沸混合冷媒の、各突起との衝突による流速の低下が
可及的に抑えられ得て、かかる非共沸混合冷媒の突起と
の衝突による乱流促進が、更に助長せしめられ得ること
となる。Further, in the condensation promoting heat transfer tube according to the present invention, the height of the projection having the shape of a truncated quadrangular pyramid is in the range of 0.15 to 0.40 mm, and the four bases of the projection are particularly provided. However, since each of the projections is smaller than the width of the first groove and the second groove, each of the projections is sufficient to cause turbulent flow promotion due to collision of the non-azeotropic mixed refrigerant with the projection. It is made as small as possible after securing a large size, whereby the flow velocity of the non-azeotropic mixed refrigerant flowing between the projections due to collision with each projection is reduced as much as possible. And the turbulent flow promotion due to the collision of the non-azeotropic refrigerant mixture with the projections can be further promoted.
【0010】それ故、このような凝縮促進型伝熱管にお
いては、四角錐台形状を呈する多数の突起が形成されて
いることにより得られる非共沸混合冷媒の乱流促進作用
と、そのような突起の一つ一つが比較的に小さくされて
いることにより得られる乱流促進の助長作用とが相俟っ
て、たとえ、管内を流通せしめられる非共沸混合冷媒の
質量速度が小さい場合にあっても、かかる非共沸混合冷
媒の乱流促進が、従来のクロス溝付伝熱管に比して、よ
り有効に図られ得ることとなり、それによって、各突起
間を流通せしめられる非共沸混合冷媒が十分に撹拌され
得て、非共沸混合冷媒特有の濃度境界層の形成が効果的
に抑制され得るのである。Therefore, in such a condensation promoting type heat transfer tube, a turbulent flow promoting action of a non-azeotropic mixed refrigerant obtained by forming a large number of projections having a truncated quadrangular pyramid shape, and the like. Combined with the effect of promoting turbulence obtained by making each of the projections relatively small, even when the mass velocity of the non-azeotropic mixed refrigerant flowing through the pipe is small, However, the promotion of the turbulent flow of the non-azeotropic mixed refrigerant can be more effectively achieved as compared with the conventional cross-grooved heat transfer tubes, and as a result, the non-azeotropic mixed refrigerant can be distributed between the projections. The refrigerant can be sufficiently stirred, and the formation of the concentration boundary layer peculiar to the non-azeotropic refrigerant mixture can be effectively suppressed.
【0011】従って、かくの如き本発明に従う凝縮促進
型伝熱管にあっては、非共沸混合冷媒が、管内を、15
0kg/(m2 ・s)以下の低冷媒質量速度で流通せし
められる際における管内凝縮熱伝達率の低下が可及的に
抑制され得、それによって、空調機用熱交換器の中間能
力運転域における凝縮能力を有利に高め得るのであり、
その結果として、空調機用熱交換器のエネルギー消費量
の低減に大きく寄与せしめ得ることとなるのである。Therefore, in the condensation promoting type heat transfer tube according to the present invention as described above, the non-azeotropic mixed refrigerant flows in the tube for 15 hours.
A decrease in the condensed heat transfer coefficient in the pipe when flowing at a low refrigerant mass velocity of 0 kg / (m 2 · s) or less can be suppressed as much as possible, whereby the intermediate capacity operation range of the heat exchanger for the air conditioner can be suppressed. Can advantageously increase the condensation capacity at
As a result, the energy consumption of the air conditioner heat exchanger can be greatly reduced.
【0012】また、本発明にあっては、前述せる第二の
技術的課題を解決するために、伝熱管内を150kg/
(m2 ・s)以下の低冷媒質量速度で流通せしめられる
非共沸混合冷媒を凝縮せしめる方法であって、管内面
に、管軸に対して20〜40°の捻れ角と0.20〜
0.35mmの深さとを有する第一の溝が、管軸方向に
連続して延びるように複数形成されると共に、該第一の
溝の捻れ角に対して±5°の範囲内の大きさの捻れ角
と、該第一の溝の深さに対して±0.05mmの範囲内
の深さとを有する第二の溝が、管軸に平行な直線を該第
一の溝との間に挟むようにして、該第一の溝と交差しつ
つ、管軸方向に連続して延びるように複数形成されて、
それら複数の第一の溝と第二の溝のうち、周方向に隣り
合う二つの第一の溝と二つの第二の溝とにて囲まれてな
る突起が、0.15〜0.40mmの高さと、該第一及
び第二の溝のそれぞれの幅よりも小さい長さの四つの底
辺を有する四角錐台形状をもって、該第一の溝と該第二
の溝を介して千鳥状に、相互に独立して、多数形成され
てなる凝縮促進型伝熱管を用い、前記非共沸混合冷媒
を、かかる凝縮促進型伝熱管内に流通せしめつつ、冷却
することにより、凝縮せしめるようにしたことを特徴と
する非共沸混合冷媒の凝縮方法をも、その要旨とするも
のである。Further, in the present invention, in order to solve the above-mentioned second technical problem, the inside of the heat transfer tube is 150 kg / kg.
A method for condensing a non-azeotropic mixed refrigerant flowing at a low mass flow rate of (m 2 · s) or less, wherein a twist angle of 20 to 40 ° with respect to the pipe axis and 0.20 to
A plurality of first grooves having a depth of 0.35 mm are formed so as to extend continuously in the tube axis direction, and have a size within a range of ± 5 ° with respect to the twist angle of the first grooves. And a second groove having a torsion angle of ± 0.05 mm with respect to the depth of the first groove, a straight line parallel to the tube axis is formed between the first groove and the second groove. As it is sandwiched, a plurality is formed so as to extend continuously in the tube axis direction while intersecting with the first groove,
Among the plurality of first grooves and the second grooves, the protrusions surrounded by two first grooves and two second grooves adjacent in the circumferential direction are 0.15 to 0.40 mm. Height and a truncated quadrangular pyramid shape having four bases with a length smaller than the width of each of the first and second grooves, in a staggered manner through the first and second grooves. Independently of each other, a large number of condensation-promoting heat transfer tubes are used, and the non-azeotropic mixed refrigerant is allowed to condense by cooling while flowing through the condensation-promoting heat transfer tubes. A method for condensing a non-azeotropic mixed refrigerant characterized by the above is also the gist of the invention.
【0013】要するに、この本発明に従う非共沸混合冷
媒の凝縮方法は、非共沸混合冷媒が、管内を、150k
g/(m2 ・s)以下の低冷媒質量速度で流通せしめら
れる際における管内凝縮熱伝達率の低下を可及的に抑制
せしめ得るといった、前述せる如き優れた特徴を発揮す
る凝縮促進型伝熱管を用いて、非共沸混合冷媒の凝縮を
行うようにしたものである。[0013] In short, the method for condensing a non-azeotropic mixed refrigerant according to the present invention is as follows.
g / (m 2 · s) or less, a condensation-promoting type heat transfer medium exhibiting the above-mentioned excellent characteristics, such as being able to suppress as much as possible a decrease in the heat transfer coefficient of condensation in a pipe when flowing at a low mass flow rate of the refrigerant. The non-azeotropic mixed refrigerant is condensed by using a heat tube.
【0014】従って、このような本発明に従う非共沸混
合冷媒の凝縮方法によれば、伝熱管内を、150kg/
(m2 ・s)以下の低冷媒質量速度で流通せしめられる
非共沸混合冷媒を効率的に凝縮せしめることが出来、そ
れによって、空調機用熱交換器の中間能力運転域におけ
る凝縮能力の向上と、それに伴う空調機用熱交換器のエ
ネルギー消費量の大幅な低減とを、有利に実現せしめ得
ることが可能となるのである。Therefore, according to the method for condensing a non-azeotropic refrigerant mixture according to the present invention, the inside of the heat transfer tube is reduced to 150 kg / hour.
It is possible to efficiently condense the non-azeotropic mixed refrigerant flowing at a low refrigerant mass velocity of (m 2 · s) or less, thereby improving the condensing capacity of the air conditioner heat exchanger in the intermediate capacity operation range. In addition, it is possible to advantageously realize a significant reduction in the energy consumption of the heat exchanger for the air conditioner.
【0015】[0015]
【発明の実施の形態】以下、本発明を具体的に明らかに
するために、本発明に係る凝縮促進型伝熱管と非共沸混
合冷媒の凝縮方法の具体的な構成について、図面を参照
しつつ、詳細に説明することとする。BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, in order to specifically clarify the present invention, a specific configuration of a condensation promoting heat transfer tube and a method of condensing a non-azeotropic mixed refrigerant according to the present invention will be described with reference to the drawings. The details will be described.
【0016】先ず、図1には、本発明に従う構造を有す
る凝縮促進型伝熱管の一例が、それを管軸方向に切断し
て展開した状態において、概略的に示されている。かか
る図1からも明らかなように、本実施形態の凝縮促進型
伝熱管においては、その内面に、管軸方向に向かって螺
旋状に連続して延びる第一の溝10と第二の溝12と
が、互い交差する状態で、それぞれ複数設けられると共
に、多数の突起14が、相互に独立して形成されて、成
っている。First, FIG. 1 schematically shows an example of a condensation promoting type heat transfer tube having a structure according to the present invention in a state where the tube is cut in the tube axis direction and expanded. As is clear from FIG. 1, in the condensation promotion type heat transfer tube of the present embodiment, the first groove 10 and the second groove 12 continuously extending spirally in the tube axis direction are formed on the inner surface thereof. And a plurality of projections 14 are provided so as to intersect each other, and a large number of projections 14 are formed independently of each other.
【0017】なお、この凝縮促進型伝熱管は、図示され
てはいないものの、非共沸混合冷媒の流通路を管内部に
形成し得るように、円形や楕円形、扁平な長円形等の適
当な断面形状を呈する中空管体構造において、構成され
るものであり、また、その構成材料として、要求される
凝縮性能や採用される冷媒の種類等に応じて、例えば、
銅や銅合金、アルミニウム合金等の適当な金属材が、適
宜に用いられて、形成されるものである。更に、かかる
凝縮促進型伝熱管は、例えば、連続する一本の素管内
に、所定のプラグを回転可能に挿入した状態で、該素管
を管軸方向に引抜き移動せしめることにより、該プラグ
を回転せしめつつ、該素管内面に、該プラグの外周面に
設けられた突条に対応した溝を形成し得るように構成さ
れてなる、従来と同様な構造の転造加工装置を用いた、
公知の転造加工を行なうことによって、容易に製造され
る。なお、このような転造加工方法にて、目的とする凝
縮促進型伝熱管を得る際には、好ましくは、外周面に、
前記第一の溝10の管軸に対する捻れ角に対応した捻れ
角を有する第一の突条が設けられた第一のプラグと、外
周面に、前記第二の溝12の管軸に対応する捻れ角に対
応した捻れ角を有する第二の突条が形成された第二のプ
ラグとが、軸方向に直列に並んで、それぞれ回転可能に
連結されてなる構造のプラグが、前記素管内において、
第一のプラグが該素管の引抜き方向の前方側に位置する
ように挿入されて、用いられることとなる。Although not shown, the condensation-promoting heat transfer tube has an appropriate shape such as a circle, an ellipse, or a flat ellipse so that a flow path for the non-azeotropic refrigerant mixture can be formed inside the tube. In a hollow tube structure having a complex cross-sectional shape, it is constituted, and, as a constituent material thereof, depending on the required condensation performance and the type of refrigerant employed, for example,
An appropriate metal material such as copper, a copper alloy, or an aluminum alloy is appropriately used and formed. Further, such a condensation promoting type heat transfer tube, for example, pulls the plug in a continuous axial direction in a state where a predetermined plug is rotatably inserted into the continuous tube, and pulls the plug in the tube axis direction to move the plug. While rotating, using a rolling device having a structure similar to the conventional one, which is configured to be able to form a groove corresponding to the ridge provided on the outer peripheral surface of the plug, on the inner surface of the raw tube,
It is easily manufactured by performing a known rolling process. In addition, when the intended condensation promotion type heat transfer tube is obtained by such a rolling processing method, preferably, on the outer peripheral surface,
A first plug provided with a first ridge having a twist angle corresponding to a twist angle of the first groove 10 with respect to the tube axis, and an outer peripheral surface corresponding to the tube axis of the second groove 12. A plug having a structure in which a second plug on which a second ridge having a torsion angle corresponding to the torsion angle is formed is arranged in series in the axial direction and rotatably connected to each other in the raw tube. ,
The first plug is inserted and used so as to be located on the front side in the drawing direction of the raw tube.
【0018】そして、図1からも明らかなように、複数
の第一の溝10と第二の溝12は、何れも、管軸に対し
て直角な断面において、底部に向かうに従って次第に狭
幅となる略台形形状とされていると共に、管軸に関して
互いに対称となる状態で、該管軸に対してそれぞれ傾斜
し、且つ該管軸の延出方向に向かって螺旋状に連続して
延びる形態とされているのである。As is apparent from FIG. 1, each of the plurality of first grooves 10 and the second grooves 12 has a gradually narrowing width toward the bottom in a section perpendicular to the tube axis. A substantially trapezoidal shape, and in a state of being symmetrical with respect to the tube axis, inclined with respect to the tube axis, and continuously extending spirally in the direction in which the tube axis extends. It is being done.
【0019】かくして、凝縮促進型伝熱管の内面に、複
数の第一の溝10と第二の溝12とが、管軸に平行な直
線を間に挟むようにして、互いに交差して延びるように
形成されており、また、前記相互に独立した多数の突起
14が、複数の第一の溝10と第二の溝12のうち、周
方向に隣り合う二つの第一の溝10,10と二つの第二
の溝12,12とにて囲まれてなる四角錐台形状をもっ
て、第一の溝10と第二の溝12を介して千鳥状に配置
された状態で、形成されている。Thus, a plurality of first grooves 10 and second grooves 12 are formed on the inner surface of the condensation promoting heat transfer tube so as to extend intersecting each other with a straight line parallel to the tube axis interposed therebetween. In addition, the plurality of mutually independent projections 14 are provided with two of the first grooves 10 and 10 and two of the plurality of first grooves 10 and the second grooves 12 which are circumferentially adjacent to each other. It has a truncated quadrangular pyramid shape surrounded by the second grooves 12, 12, and is formed in a staggered manner via the first groove 10 and the second groove 12.
【0020】そして、ここでは、特に、互いに交差して
延びる第一及び第二の溝10,12において、伝熱管の
周方向隣り合う第一の溝10同士の間隔と第二の溝12
同士の間隔が、それぞれ、第一の溝10の底部の幅:W
1 と第二の溝12の底部の幅:W2 よりも小さくされて
おり、以て、それら第一の溝10と第二の溝12とにて
形成される四角錐台形状の突起14の四つの底辺の長さ
が、何れも、第一の溝10の底部の幅:W1 及び第二の
溝12の底部の幅:W2 よりも小さく為されている。Here, in particular, in the first and second grooves 10 and 12 extending crossing each other, the interval between the first grooves 10 adjacent in the circumferential direction of the heat transfer tube and the second groove 12
The interval between the two is the width of the bottom of the first groove 10: W
The width of the bottom of the first and second grooves 12 is set to be smaller than W 2 , so that the truncated quadrangular pyramid-shaped protrusions 14 formed by the first and second grooves 10 and 12 are formed. the length of the four base are both, the bottom width of the first groove 10: W 1 and the second groove 12 of the bottom width: are made smaller than W 2.
【0021】これによって、本実施形態の凝縮促進型伝
熱管にあっては、非共沸混合冷媒が、管内部を、複数の
第一の溝10と第二の溝12に沿ってスムーズに流通せ
しめられる一方で、四角錐台形状を呈する多数の突起1
4に衝突せしめられて、かかる非共沸混合冷媒の乱流が
促進されるようになっているのである。Thus, in the condensation-promoting heat transfer tube of the present embodiment, the non-azeotropic mixed refrigerant flows smoothly inside the tube along the plurality of first grooves 10 and the second grooves 12. Many protrusions 1 exhibiting a truncated quadrangular pyramid shape
4, the turbulent flow of the non-azeotropic refrigerant mixture is promoted.
【0022】なお、かかる凝縮促進型伝熱管において
は、前述せる如く、管軸方向に向かって螺旋状に延びる
第一の溝10と第二の溝12とが、管軸に関して互いに
対称となるように延出せしめられており、換言すれば、
螺旋溝からなる第一の溝10の管軸に対する捻れ角(リ
ード角):αと、同じく螺旋溝からなる第二の溝12の
管軸に対する捻れ角(リード角):βとが同一の大きさ
とされているが、第二の溝12の捻れ角:βが、第一の
溝10の捻れ角:αに対して±5°の範囲内の大きさと
されている必要がある。つまり、第一の溝10の捻れ
角:αと第二の溝12の捻れ角:βとの差が5°以内と
されていなければならないのである。何故なら、第一の
溝10の捻れ角:αと第二の溝12の捻れ角:βとの差
が5°よりも大きくされる場合には、それらの捻れ角の
差が大きくなり過ぎて、管内を流通せしめられる非共沸
混合冷媒が、第一の溝10と第二の溝12のうち、捻れ
角の小さな方の溝に沿って、より多く流通せしめられる
こととなって、第一の溝10と第二の溝12に沿った非
共沸混合冷媒の流通量のバランスが崩れてしまい、それ
によって、かかる非共沸混合冷媒の前記多数の突起14
への衝突による乱流促進作用が低下せしめられることと
なるからである。In the condensation promoting heat transfer tube, as described above, the first groove 10 and the second groove 12 spirally extending in the tube axis direction are symmetric with respect to the tube axis. Has been extended to, in other words,
The torsion angle (lead angle): α of the first groove 10 formed of a spiral groove with respect to the tube axis is equal to the torsion angle (lead angle) of the second groove 12 formed of the spiral groove with respect to the tube axis. However, it is necessary that the twist angle β of the second groove 12 is within ± 5 ° of the twist angle α of the first groove 10. That is, the difference between the twist angle α of the first groove 10 and the twist angle β of the second groove 12 must be within 5 °. If the difference between the twist angle α of the first groove 10 and the twist angle β of the second groove 12 is made larger than 5 °, the difference between the twist angles becomes too large. Therefore, the non-azeotropic mixed refrigerant circulated in the pipe is circulated more along the smaller of the twist angles of the first groove 10 and the second groove 12, and The balance of the flow rate of the non-azeotropic mixed refrigerant along the groove 10 and the second groove 12 is broken, and the large number of protrusions 14 of the non-azeotropic mixed refrigerant
This is because the turbulence promoting effect due to the collision with the air is reduced.
【0023】また、第二の溝12の捻れ角:βの大きさ
の基準となる第一の溝10の捻れ角:αの大きさは、2
0〜40°とされることとなる。第一の溝10の管軸に
対する捻れ角:αが20°未満の場合には、それら第一
及び第二の溝10,12にて形成される突起14の底部
の対向する二つの角部の角度が小さくなり過ぎて、それ
らの角部に衝突せしめられる非共沸混合冷媒の乱流が十
分に促進され得なくなってしまうからであり、また、管
軸に対する捻れ角が40°を越えるような螺旋溝は、容
易には形成され得ないため、かかる第一の溝10の捻れ
角:αが40°を越える場合には、該第一の溝10、ひ
いては凝縮促進型伝熱管の製造が困難となるからであ
る。The magnitude of the torsion angle α of the first groove 10 which is a reference for the magnitude of the torsion angle β of the second groove 12 is 2
0 to 40 °. When the twist angle α of the first groove 10 with respect to the pipe axis is less than 20 °, two opposite corners of the bottom of the projection 14 formed by the first and second grooves 10 and 12 are formed. This is because the angle becomes too small, and the turbulent flow of the non-azeotropic mixed refrigerant that collides with those corners cannot be sufficiently promoted, and the twist angle with respect to the tube axis exceeds 40 °. Since the spiral groove cannot be easily formed, when the twist angle α of the first groove 10 exceeds 40 °, it is difficult to manufacture the first groove 10 and, consequently, the condensation promoting heat transfer tube. This is because
【0024】さらに、第二の溝12の深さ:D2 も、第
一の溝10の深さ:D1 に対して±0.05mmの範囲
内となるような略同一の寸法とされている必要がある。
かかる第二の溝12の深さ:D2 が、第一の溝10の深
さ:D1 に対して±0.05mmを越えた寸法とされる
場合には、それら第一の溝10と第二の溝12のそれぞ
れの管軸に対する捻れ角の差が大きくされた場合と同様
に、伝熱管内部において、非共沸混合冷媒が、第一の溝
10と第二の溝12のうち、深さの深い方の溝に沿っ
て、より多く流通せしめられることとなって、第一の溝
10と第二の溝12に沿った非共沸混合冷媒の流通量の
バランスが崩れてしまい、それによって、非共沸混合冷
媒の前記多数の突起14への衝突による乱流促進作用が
低下せしめられるようになる。Furthermore, the depth of the second groove 12: D 2 also, the depth of the first groove 10: is substantially the same dimensions so as to be in the range of ± 0.05mm with respect to D 1 Need to be.
The depth of such second groove 12: D 2 is the depth of the first groove 10: If it is a dimension beyond ± 0.05mm with respect to D 1 is, those first grooves 10 of the As in the case where the difference between the twist angles of the second grooves 12 with respect to the respective tube axes is increased, in the heat transfer tube, the non-azeotropic mixed refrigerant contains the first groove 10 and the second groove 12. Along the deeper groove, more will be circulated, the balance of the non-azeotropic refrigerant mixture along the first groove 10 and the second groove 12 will be lost, As a result, the turbulent flow promoting effect due to the collision of the non-azeotropic refrigerant mixture with the plurality of projections 14 is reduced.
【0025】また、第二の溝12の深さ:D2 の基準と
なる第一の溝10の深さ:D1 は、0.20〜0.35
mmとされる。けだし、第一の溝10の深さ:D1 が
0.20mm未満である場合には、第一の溝10と第二
の溝12とにて形成される突起14の高さが低くなり過
ぎて、突起14が、伝熱管内部を流通せしめられる非共
沸混合冷媒と衝突する障害物としての機能を果たし得な
くなってしまい、それによって、非共沸混合冷媒の突起
14への衝突による乱流促進を十分に図ることが出来な
くなるからであり、また、限られた肉厚を有する伝熱管
の内面には、0.35mmを越える深さの溝が、容易に
は形成され得ないため、かかる第一の溝10の深さ:D
1 を越える場合には、該第一の溝10、ひいては凝縮促
進型伝熱管の製造が困難となるからである。Further, the depth of the second groove 12: the depth of the first groove 10 as a reference of D 2: D 1 is 0.20 to 0.35
mm. Capped, the depth of the first groove 10: when D 1 is less than 0.20mm, the height of the protrusions 14 formed in the first groove 10 of the second groove 12. becomes too low As a result, the protrusion 14 cannot function as an obstacle that collides with the non-azeotropic refrigerant mixed in the heat transfer tube. This is because it is not possible to achieve sufficient promotion, and a groove having a depth exceeding 0.35 mm cannot be easily formed on the inner surface of the heat transfer tube having a limited wall thickness. Depth of first groove 10: D
If it exceeds 1 , it is difficult to manufacture the first groove 10 and, consequently, the condensation promoting heat transfer tube.
【0026】一方、第一の溝10と第二の溝12とにて
形成される突起14は、その高さ:hが、第一及び第二
の溝10,12のそれぞれの深さに依存せしめられるこ
ととなるが、ここでは、かかる突起14の高さ:hが、
0,15〜0.40mmの範囲内とされることとなる。
この突起14の高さ:hが、0.15mmを下回る場合
には、第一及び第二の溝10,12の深さが浅すぎる場
合と同様に、突起14が、低過ぎて、非共沸混合冷媒と
衝突する障害物としての機能を失ってしまい、それによ
って、非共沸混合冷媒の突起14への衝突による乱流促
進作用が低下してしまうからであり、また、0.40m
mを越える大きな高さの突起14を形成するためには、
第一及び第二の溝10,12の深さを、上述の如き範囲
を超えて、過剰に深くしなければならなくなり、その場
合には、突起14、ひいては凝縮促進型伝熱管の製造が
困難となるようになる。On the other hand, the height h of the projection 14 formed by the first groove 10 and the second groove 12 depends on the depth of each of the first and second grooves 10 and 12. In this case, the height of the projection 14 is h.
It will be in the range of 0.15 to 0.40 mm.
When the height h of the projections 14 is less than 0.15 mm, the projections 14 are too low and non-coincidence as in the case where the depths of the first and second grooves 10 and 12 are too shallow. This is because the function as an obstacle that collides with the boiling mixed refrigerant is lost, and thereby the turbulence promoting effect due to the collision of the non-azeotropic mixed refrigerant with the projections 14 is reduced.
In order to form a projection 14 having a large height exceeding m.
The depths of the first and second grooves 10, 12 must be excessively deeper than the above-mentioned range, in which case it is difficult to manufacture the projections 14, and consequently the condensation promoting heat transfer tubes. It becomes to become.
【0027】そして、このような構造とされた本実施形
態の凝縮促進型伝熱管は、従来と同様に、例えば、水平
方向に延びるように配置された状態で、管外にアルミニ
ウム製の放熱フィンが拡管装着せしめられることによ
り、ルームエアコンやパッケージエアコン等の如き空調
用熱交換器の凝縮器として構成され、また、この凝縮器
において、非共沸混合冷媒、例えば、HFC−32とH
FC−125とHFC−134aをそれぞれ所定の割合
にて混合してなる冷媒や、HFC−32とHFC−12
5フを混合した冷媒等を凝縮せしめられるのに使用され
ることとなる。The condensation promoting heat transfer tube according to the present embodiment having such a structure is, for example, disposed in such a manner as to extend in the horizontal direction, and is provided with aluminum radiating fins outside the tube as in the prior art. Is installed as a condenser of an air-conditioning heat exchanger such as a room air conditioner or a package air conditioner. In this condenser, a non-azeotropic mixed refrigerant such as HFC-32 and HFC is used.
Refrigerant obtained by mixing FC-125 and HFC-134a at a predetermined ratio, HFC-32 and HFC-12a
It is used to condense a refrigerant or the like mixed with 5 f.
【0028】つまり、凝縮器として構成された凝縮促進
型伝熱管内に、非共沸混合冷媒を、前述の如く、複数の
第一の溝10と第二の溝12に沿って流通せしめて、そ
れら第一及び第二の溝10,12にて形成される多数の
突起14に衝突させることにより、かかる非共沸混合冷
媒の乱流を促進する。そして、その一方で、伝熱管の外
部に流動せしめられて、管外面に接触する冷却用空気や
冷却水等にて、乱流が促進された非共沸混合冷媒を冷却
して、凝縮するのである。That is, the non-azeotropic refrigerant mixture is allowed to flow along the plurality of first grooves 10 and the second grooves 12 in the condensation promoting heat transfer tube configured as a condenser, as described above. By colliding with many protrusions 14 formed by the first and second grooves 10, 12, the turbulent flow of the non-azeotropic refrigerant mixture is promoted. And on the other hand, the non-azeotropic mixed refrigerant in which turbulence is promoted is cooled and condensed by cooling air or cooling water which is made to flow outside the heat transfer tube and comes into contact with the outer surface of the tube. is there.
【0029】このように、本実施形態の凝縮促進型伝熱
管においては、内面に、非共沸混合冷媒がバランス良く
流通せしめられるように構成された複数の第一の溝10
と第二の溝12とが、互いに交差しつつ、管軸方向に連
続して延びるように形成されていることにより、四角錐
台形状の多数の突起14が、千鳥状に配置された状態
で、相互に独立して、形成されているところから、管内
を流通せしめられる非共沸混合冷媒が、それら多数の突
起14に衝突して、乱流が効果的に促進され得るのであ
り、また、かかる非共沸混合冷媒において、第一の溝1
0と第二の溝12に沿って流通せしめられる冷媒と、突
起14の斜面や斜辺に沿って流通せしめられる冷媒との
間に速度分布が生じ、それによっても、非共沸混合冷媒
の乱流促進が、より有効に図られ得ることとなる。As described above, in the condensation promoting type heat transfer tube of the present embodiment, the plurality of first grooves 10 configured to allow the non-azeotropic mixed refrigerant to flow in a balanced manner on the inner surface.
And the second groove 12 are formed so as to extend continuously in the pipe axis direction while intersecting with each other, so that a large number of truncated quadrangular pyramid-shaped protrusions 14 are arranged in a staggered manner. Independently of each other, the non-azeotropic refrigerant circulated in the pipe from the formed portion collides with the large number of projections 14, and turbulence can be effectively promoted. In such a non-azeotropic mixed refrigerant, the first groove 1
The velocity distribution occurs between the refrigerant circulated along the zero and the second groove 12 and the refrigerant circulated along the slope or the hypotenuse of the projection 14, thereby also causing the turbulent flow of the non-azeotropic mixed refrigerant. Promotion can be achieved more effectively.
【0030】加えて、かかる凝縮促進型伝熱管において
は、各突起14が、管内を流通せしめられる非共沸混合
冷媒の障害物として十分に機能し得る最低限の高さを確
保しつつ、四つの底辺の長さが第一及び第二の溝10,
12の底部側の幅よりも小さくされていることにより、
全体の大きさが可及的に小さくされ、それによって、管
内を流通せしめられる非共沸混合冷媒の、各突起14と
の衝突による流速の低下が可及的に抑えられ得て、かか
る非共沸混合冷媒の突起14との衝突による乱流促進
が、更に助長せしめられ得るのである。In addition, in such a condensation promotion type heat transfer tube, each projection 14 has a minimum height which can sufficiently function as an obstacle for the non-azeotropic mixed refrigerant flowing through the tube, while maintaining the minimum height. The length of the bottoms of the first and second grooves 10,
12 is smaller than the width on the bottom side,
The overall size is made as small as possible, so that the flow rate of the non-azeotropic mixed refrigerant flowing through the pipe due to collision with each projection 14 can be suppressed as much as possible. The promotion of the turbulent flow due to the collision of the boiling mixed refrigerant with the projections 14 can be further promoted.
【0031】それ故、本実施形態においては、非共沸混
合冷媒が、管内を低冷媒質量速度域で流通せしめられる
場合にあっても、そのような非共沸混合冷媒の乱流促進
が、従来管に比して、より有効に図られ得て、管内を流
通せしめられる非共沸混合冷媒が、更に一層十分に撹拌
され得ることとなり、以て非共沸混合冷媒特有の濃度境
界層の形成が効果的に抑制され得ることとなる。Therefore, in the present embodiment, even when the non-azeotropic mixed refrigerant is circulated in the pipe at a low refrigerant mass velocity range, such non-azeotropic mixed refrigerant promotes turbulent flow. Compared to the conventional pipe, the non-azeotropic mixed refrigerant that can be more effectively achieved and can be circulated in the pipe can be further sufficiently stirred, and thus the concentration boundary layer unique to the non-azeotropic mixed refrigerant can be obtained. The formation can be effectively suppressed.
【0032】従って、このような本実施形態の凝縮促進
型伝熱管にあっては、非共沸混合冷媒が、管内を、15
0kg/(m2 ・s)以下の低冷媒質量速度で流通せし
められる際における管内凝縮熱伝達率の低下が可及的に
抑制され得るのである。そして、その結果、かかる凝縮
促進型伝熱管にて構成された凝縮器が組み付けられてな
る空調機用熱交換器の中間能力運転域における凝縮能力
を有利に高め得て、そのエネルギー消費量を大幅に低減
せしめることが出来るのである。Therefore, in such a condensation promoting type heat transfer tube of the present embodiment, the non-azeotropic mixed refrigerant flows through the tube for 15 seconds.
When the refrigerant is allowed to flow at a low refrigerant mass velocity of 0 kg / (m 2 · s) or less, a decrease in the in-pipe condensation heat transfer coefficient can be suppressed as much as possible. As a result, it is possible to advantageously increase the condensation capacity in the intermediate capacity operation range of the air conditioner heat exchanger in which the condenser configured with the condensation promotion type heat transfer tube is assembled, and significantly reduce the energy consumption. It can be reduced to less.
【0033】因みに、本発明に従う構造を有する凝縮促
進型伝熱管が、上述の如き優れた特徴を発揮するもので
あることを確認するために、本発明者等が行った、かか
る凝縮促進型伝熱管の評価試験について、以下に示す。Incidentally, in order to confirm that the condensation promoting heat transfer tube having the structure according to the present invention exhibits the above-mentioned excellent characteristics, the present inventors conducted such condensation promoting heat transfer tube. The evaluation test of the heat tube is shown below.
【0034】すなわち、先ず、複数の第一の溝と第二の
溝とが、管軸方向に向かって螺旋状に連続し、且つ互い
に交差して延びる形態をもって管内面に形成されること
により、四角錐台形状の多数の突起が、千鳥状に配置さ
れた状態で、相互に独立して形成されると共に、下記表
1に示されるような寸法諸元を有して構成されてなる、
本発明に従う構造とされた4種類の凝縮促進型伝熱管
(実施例1〜実施例4)を形成して、準備した。また、
比較のために、管内面に、第一の溝のみが多数設けられ
てなる従来の螺旋溝付伝熱管(比較例1)と、第一の溝
と第二の溝とが設けられるものの、第一の溝の管軸に対
する捻れ角が本発明の範囲外とされ、且つ突起の底辺の
長さが第一及び第二の溝の底部の幅よりも大きくされた
クロス溝付伝熱管(比較例2)と、管内面に、V字形状
を呈する溝(表1には、第一の溝として示した)が多数
形成されてなる従来の松葉溝付伝熱管(比較例3)と
を、それぞれ、下記表1に示されるような寸法諸元をも
って形成して、準備した。That is, first, a plurality of first grooves and second grooves are formed on the inner surface of the pipe in a form that is spirally continuous in the pipe axis direction and extends so as to intersect with each other. A large number of projections having a truncated quadrangular pyramid shape are formed independently of each other in a staggered state, and are configured to have dimensional specifications as shown in Table 1 below.
Four types of condensation promoting heat transfer tubes (Examples 1 to 4) having a structure according to the present invention were formed and prepared. Also,
For comparison, a conventional spiral grooved heat transfer tube (Comparative Example 1) in which only a first groove is provided on the inner surface of the tube and a first groove and a second groove are provided on the inner surface of the tube. A heat transfer tube with cross grooves in which the twist angle of one groove with respect to the tube axis is out of the range of the present invention, and the length of the base of the projection is larger than the width of the bottom of the first and second grooves (Comparative Example) 2) and a conventional Matsuba grooved heat transfer tube (Comparative Example 3) in which a number of V-shaped grooves (shown as first grooves in Table 1) are formed on the inner surface of the tube, respectively. , And were prepared with dimensional specifications as shown in Table 1 below.
【0035】なお、これら準備された7種類の凝縮促進
型伝熱管(実施例1〜4及び比較例1〜3)は、全て、
銅材質のものとした。また、下記表1において、リード
角は、第一の溝又は第二の溝の管軸に対する捩じれ角の
大きさを示し、条数は、第一の溝又は第二の溝の1周当
たりの条数、即ち、管軸に垂直な断面において、その端
面に形成される第一の溝又は第二の溝の数を示す。The prepared seven types of condensation promoting heat transfer tubes (Examples 1 to 4 and Comparative Examples 1 to 3) are all
It was made of copper. In Table 1 below, the lead angle indicates the magnitude of the torsion angle of the first groove or the second groove with respect to the tube axis, and the number of threads is per revolution of the first groove or the second groove. The number of the grooves, that is, the number of the first grooves or the second grooves formed on the end surface in a cross section perpendicular to the tube axis.
【0036】[0036]
【表1】 [Table 1]
【0037】次いで、それら準備された7種類の凝縮促
進型伝熱管(実施例1〜4及び比較例1〜3)と、従来
より公知の伝熱性能試験装置と、冷媒としてR−407
C(23mass%HFC−32/25mass%HF
C−125/52mass%HFC−134a)とを用
い、かかる伝熱性能試験装置の試験セクションに対し
て、各種伝熱管を単管で組み付けて、図2に示される如
き冷媒の流通下で、下記表2に示される試験条件によ
り、凝縮性能試験を、公知の方法に従って実施し、各種
伝熱管における非共沸混合冷媒の質量速度に応じた管内
凝縮熱伝達率を測定した。そして、かくして得られた、
それぞれの伝熱管の冷媒質量速度に応じた管内凝縮熱伝
達率の測定値のうち、第一の溝と第二の溝とが互いに交
差するように設けられた従来のクロス溝付伝熱管(比較
例2)の、冷媒質量速度を50kg/(m2 ・s)とし
た際の管内凝縮熱伝達率を基準(=1.0)として、各
凝縮促進型伝熱管(実施例1〜4及び比較例1〜3)に
おける冷媒質量速度に応じた管内凝縮熱伝達率の、該基
準となる管内凝縮熱伝達率に対する比率を、それぞれ求
めた。その結果から得られた、各凝縮促進型伝熱管(実
施例1〜4及び比較例1〜3)の管内凝縮熱伝達率比と
冷媒質量速度との関係を、図3に示した。なお、凝縮性
能試験における試験区間長さは、4mとした。Next, the prepared seven types of condensation promoting heat transfer tubes (Examples 1 to 4 and Comparative Examples 1 to 3), a conventionally known heat transfer performance test device, and R-407 as a refrigerant.
C (23 mass% HFC-32 / 25 mass% HF
C-125 / 52 mass% HFC-134a), various heat transfer tubes were assembled in a single tube with respect to the test section of the heat transfer performance test device, and under the flow of a refrigerant as shown in FIG. Under the test conditions shown in Table 2, a condensation performance test was performed according to a known method, and the in-tube condensation heat transfer coefficient in each heat transfer tube was measured in accordance with the mass velocity of the non-azeotropic mixed refrigerant. And thus obtained,
Among the measured values of the in-tube condensed heat transfer coefficient according to the refrigerant mass velocity of each heat transfer tube, a conventional cross-groove heat transfer tube provided so that the first groove and the second groove intersect each other (comparison) Each condensation-promoting heat transfer tube (Examples 1 to 4 and Comparative Example 1) was used with reference to the condensation heat transfer coefficient in the tube when the mass velocity of the refrigerant was 50 kg / (m 2 · s) in Example 2) (= 1.0). The ratio of the in-pipe condensation heat transfer coefficient according to the refrigerant mass velocity in Examples 1 to 3) to the reference in-pipe condensation heat transfer coefficient was determined. FIG. 3 shows the relationship between the condensation heat transfer coefficient ratio in each of the condensation promoting heat transfer tubes (Examples 1 to 4 and Comparative Examples 1 to 3) and the refrigerant mass velocity obtained from the results. The test section length in the condensation performance test was 4 m.
【0038】[0038]
【表2】 [Table 2]
【0039】図3に示される結果から明らかなように、
本発明に従う構造を有する4種類の凝縮促進型伝熱管
(実施例1〜4)にあっては、150kg/(m2 ・
s)以下の低冷媒質量速度域における管内凝縮熱伝達率
比が、200kg/(m2 ・s)程度の中間冷媒質量速
度域における管内凝縮熱伝達率比に比して、それほど大
きな変化が見られない。これに対して、従来の一般的な
クロス溝付伝熱管(比較例2)と螺旋溝付伝熱管(比較
例1)と松葉溝付伝熱管(比較例3)においては、15
0kg/(m2 ・s)以下の低冷媒質量速度域における
管内凝縮熱伝達率比が、冷媒質量速度が小さくなる従っ
て、200kg/(m2 ・s)程度の中間冷媒質量速度
域における管内凝縮熱伝達率比に比べて、大幅に低減せ
しめられることとなる。As is clear from the results shown in FIG.
In the four types of condensation promoting heat transfer tubes having the structure according to the present invention (Examples 1 to 4), 150 kg / (m 2 ···
s) The condensed heat transfer coefficient ratio in the pipe in the low refrigerant mass velocity range below is not so large as compared with the condensed heat transfer coefficient ratio in the intermediate refrigerant mass velocity range of about 200 kg / (m 2 · s). I can't. On the other hand, in the conventional general heat transfer tubes with cross grooves (Comparative Example 2), heat transfer tubes with spiral grooves (Comparative Example 1), and heat transfer tubes with Matsuba groove (Comparative Example 3), 15
The condensation heat transfer coefficient ratio in the pipe in the low refrigerant mass velocity region of 0 kg / (m 2 · s) or less is smaller than the refrigerant mass velocity, so that the condensation in the pipe in the intermediate refrigerant mass velocity region of about 200 kg / (m 2 · s) is achieved. The heat transfer coefficient ratio is greatly reduced as compared with the heat transfer coefficient ratio.
【0040】このことから、本発明に従う構造を有する
凝縮促進型伝熱管(実施例1〜4)においては、従来の
凝縮促進型伝熱管とは異なり、非共沸混合冷媒が、管内
を150kg/(m2 ・s)以下の低冷媒質量速度で流
通せしめられる際における管内凝縮熱伝達率の低下が、
可及的に抑制され得ることが明確に認識され得るのであ
る。Therefore, unlike the conventional condensation promoting heat transfer tubes having the structure according to the present invention, the non-azeotropic mixed refrigerant in the condensation promoting heat transfer tubes having the structure according to the present invention is 150 kg / tube. (M 2 · s) when the refrigerant is allowed to flow at a low mass flow rate of the refrigerant,
It can be clearly recognized that it can be suppressed as much as possible.
【0041】以上、本発明の具体的な構成について詳述
してきたが、これはあくまでも例示に過ぎないのであっ
て、本発明は、上記の記載によって、何等の制約をも受
けるものではなく、当業者の知識に基づいて種々なる変
更、修正、改良等を加えた態様において実施され得るも
のである。そして、そのような実施形態が、本発明の趣
旨を逸脱しない限り、何れも、本発明の範囲内に含まれ
るものであることは、言うまでもないところである。Although the specific configuration of the present invention has been described in detail above, this is merely an example, and the present invention is not limited by the above description, and the present invention is not limited thereto. The present invention can be implemented in an aspect in which various changes, modifications, improvements, and the like are made based on the knowledge of a trader. It goes without saying that all such embodiments are included in the scope of the present invention unless they depart from the gist of the present invention.
【0042】[0042]
【発明の効果】以上の説明からも明らかなように、本発
明に従う凝縮促進型伝熱管にあっては、非共沸混合冷媒
が、管内を、150kg/(m2 ・s)以下の低冷媒質
量速度で流通せしめられる際における管内凝縮熱伝達率
の低下が可及的に抑制され得るのであり、それによっ
て、空調機用熱交換器の中間能力運転域における凝縮能
力を有利に高め得て、該空調機用熱交換器のエネルギー
消費量を大幅に低減せしめることが出来るのである。As is clear from the above description, in the condensation-promoting heat transfer tube according to the present invention, the non-azeotropic mixed refrigerant flows in the tube at a low refrigerant of 150 kg / (m 2 · s) or less. The decrease in the condensed heat transfer coefficient in the pipe when flowing at the mass velocity can be suppressed as much as possible, whereby the condensing capacity in the intermediate capacity operation range of the air conditioner heat exchanger can be advantageously increased, The energy consumption of the air conditioner heat exchanger can be greatly reduced.
【0043】また、本発明に従う非共沸混合冷媒の凝縮
方法によれば、伝熱管内を、150kg/(m2 ・s)
以下の低冷媒質量速度で流通せしめられる非共沸混合冷
媒を効率的に凝縮せしめることが出来、それによって、
空調機用熱交換器の中間能力運転域における凝縮能力の
向上と、それに伴う空調機用熱交換器のエネルギー消費
量の大幅な低減とを、有利に実現せしめ得ることが可能
となるのである。Further, according to the method for condensing a non-azeotropic mixed refrigerant according to the present invention, the inside of the heat transfer tube is set at 150 kg / (m 2 · s).
It is possible to efficiently condense the non-azeotropic refrigerant circulated at the following low refrigerant mass velocity, thereby
It is possible to advantageously achieve an improvement in the condensation capacity in the intermediate capacity operation range of the air conditioner heat exchanger and a concomitant reduction in the energy consumption of the air conditioner heat exchanger.
【図1】本発明に従う凝縮促進型伝熱管の一例の展開説
明図である。FIG. 1 is a development explanatory view of an example of a condensation promoting type heat transfer tube according to the present invention.
【図2】実施例又は比較例としての各種凝縮促進型伝熱
管の凝縮時の伝熱性能を測定する試験装置における冷媒
の流通状態を示す説明図である。FIG. 2 is an explanatory view showing a refrigerant flowing state in a test device for measuring heat transfer performance during condensation of various condensation promotion type heat transfer tubes as examples or comparative examples.
【図3】実施例及び比較例としての各種凝縮促進型伝熱
管について、それぞれのものにおける管内凝縮熱伝達率
と冷媒質量速度との関係を示すグラフである。FIG. 3 is a graph showing the relationship between the in-pipe condensation heat transfer coefficient and the refrigerant mass velocity in various condensation promoting heat transfer tubes as examples and comparative examples.
10 第一の溝 12 第二の溝 14 突起 DESCRIPTION OF SYMBOLS 10 First groove 12 Second groove 14 Projection
Claims (2)
低冷媒質量速度で流通せしめられる非共沸混合冷媒を凝
縮せしめるための凝縮促進型伝熱管にして、 管内面に、管軸に対して20〜40°の捻れ角と0.2
0〜0.35mmの深さとを有する第一の溝が、管軸方
向に連続して延びるように複数形成されると共に、該第
一の溝の捻れ角に対して±5°の範囲内の大きさの捻れ
角と、該第一の溝の深さに対して±0.05mmの範囲
内の深さとを有する第二の溝が、管軸に平行な直線を該
第一の溝との間に挟むようにして、該第一の溝と交差し
つつ、管軸方向に連続して延びるように複数形成され
て、それら複数の第一の溝と第二の溝のうち、周方向に
隣り合う二つの第一の溝と二つの第二の溝とにて囲まれ
てなる突起が、0.15〜0.40mmの高さと、該第
一及び第二の溝のそれぞれの幅よりも小さい長さの四つ
の底辺を有する四角錐台形状をもって、該第一の溝と該
第二の溝を介して千鳥状に、相互に独立して、多数形成
されていることを特徴とする凝縮促進型伝熱管。1. A condensation-promoting heat transfer tube for condensing a non-azeotropic mixed refrigerant circulating at a low mass flow rate of 150 kg / (m 2 · s) or less in a pipe. 20 to 40 ° twist angle and 0.2
A plurality of first grooves having a depth of 0 to 0.35 mm are formed so as to extend continuously in the tube axis direction, and are within ± 5 ° of the twist angle of the first grooves. A second groove having a torsion angle of magnitude and a depth in the range of ± 0.05 mm with respect to the depth of the first groove is formed by forming a straight line parallel to the tube axis with the first groove. A plurality of first grooves and second grooves are formed so as to be interposed therebetween and extend continuously in the pipe axis direction while intersecting with the first grooves, and are adjacent to each other in the circumferential direction. The protrusion surrounded by the two first grooves and the two second grooves has a height of 0.15 to 0.40 mm and a length smaller than the width of each of the first and second grooves. It has a quadrangular truncated pyramid shape having four bases, and is formed in a zigzag manner through the first groove and the second groove, independently of each other, and a large number is formed. Condensation promoting type heat transfer tube.
下の低冷媒質量速度で流通せしめられる非共沸混合冷媒
を凝縮せしめる方法であって、 管内面に、管軸に対して20〜40°の捻れ角と0.2
0〜0.35mmの深さとを有する第一の溝が、管軸方
向に連続して延びるように複数形成されると共に、該第
一の溝の捻れ角に対して±5°の範囲内の大きさの捻れ
角と、該第一の溝の深さに対して±0.05mmの範囲
内の深さとを有する第二の溝が、管軸に平行な直線を該
第一の溝との間に挟むようにして、該第一の溝と交差し
つつ、管軸方向に連続して延びるように複数形成され
て、それら複数の第一の溝と第二の溝のうち、周方向に
隣り合う二つの第一の溝と二つの第二の溝とにて囲まれ
てなる突起が、0.15〜0.40mmの高さと、該第
一及び第二の溝のそれぞれの幅よりも小さい長さの四つ
の底辺を有する四角錐台形状をもって、該第一の溝と該
第二の溝を介して千鳥状に、相互に独立して、多数形成
されてなる凝縮促進型伝熱管を用い、前記非共沸混合冷
媒を、かかる凝縮促進型伝熱管内に流通せしめつつ、冷
却することにより、凝縮せしめるようにしたことを特徴
とする非共沸混合冷媒の凝縮方法。2. A method for condensing non-azeotropic mixed refrigerant flowing at a low mass flow rate of 150 kg / (m 2 · s) or less in a heat transfer tube, comprising: Twist angle of ~ 40 ° and 0.2
A plurality of first grooves having a depth of 0 to 0.35 mm are formed so as to extend continuously in the tube axis direction, and are within ± 5 ° of the twist angle of the first grooves. A second groove having a torsion angle of magnitude and a depth in the range of ± 0.05 mm with respect to the depth of the first groove is formed by forming a straight line parallel to the tube axis with the first groove. A plurality of first grooves and second grooves are formed so as to be interposed therebetween and extend continuously in the pipe axis direction while intersecting with the first grooves, and are adjacent to each other in the circumferential direction. The protrusion surrounded by the two first grooves and the two second grooves has a height of 0.15 to 0.40 mm and a length smaller than the width of each of the first and second grooves. A large number of trapezoidal pyramid shapes having four bases are formed in a staggered manner through the first groove and the second groove, mutually independently, and a large number of condensation promoting types are formed. Using heat pipes, wherein the non-azeotropic refrigerant, while allowed to flow in such a condensation-promoting heat transfer tube, by cooling, condensation method of non-azeotropic refrigerant mixture, characterized in that as allowed to condense.
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Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102004041101A1 (en) * | 2004-08-24 | 2006-03-02 | Behr Gmbh & Co. Kg | Flat tube for a heat exchanger, in particular for motor vehicles and method for producing a flat tube |
WO2015113468A1 (en) * | 2014-01-29 | 2015-08-06 | 丹佛斯微通道换热器(嘉兴)有限公司 | Heat exchanging board and board-type heat exchanger provided with heat exchanging board |
CN107003081A (en) * | 2015-01-09 | 2017-08-01 | 三菱电机株式会社 | Heat exchanger and the refrigerating circulatory device with the heat exchanger |
-
2000
- 2000-09-01 JP JP2000265021A patent/JP3771433B2/en not_active Expired - Fee Related
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102004041101A1 (en) * | 2004-08-24 | 2006-03-02 | Behr Gmbh & Co. Kg | Flat tube for a heat exchanger, in particular for motor vehicles and method for producing a flat tube |
WO2015113468A1 (en) * | 2014-01-29 | 2015-08-06 | 丹佛斯微通道换热器(嘉兴)有限公司 | Heat exchanging board and board-type heat exchanger provided with heat exchanging board |
US10274261B2 (en) | 2014-01-29 | 2019-04-30 | Danfoss Micro Channel Heat Exchanger (Jiaxing) Co., Ltd | Heat exchanging board and board-type heat exchanger provided with heat exchanging board |
CN107003081A (en) * | 2015-01-09 | 2017-08-01 | 三菱电机株式会社 | Heat exchanger and the refrigerating circulatory device with the heat exchanger |
Also Published As
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JP3771433B2 (en) | 2006-04-26 |
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